Did you know that if you stay in the scheme while on your maternity leave, employers are unable to take the £243 tax free deduction from SMP, and therefore must pick up the tab for this themselves?
This means that you will get £243 paid into your childcare vouchers account while you are on maternity leave - a significant amount!
This benefit is not well publicised by employers, and most encourage you to leave the scheme so that SMP calculations are unaffected, but the benefits of staying in the scheme are likey to far outweigh that.
Read this thread here